<template>
  <div class="my-tab-bar">
    <div
      class="tab-item"
      v-for="(item, index) in list"
      :key="index"
      :class="{ current: index === activeIndex }"
      @click="clickFn(index, item.componentName)"
    >
      <!-- 图标, 动态class直接给字符串变量表示给元素添加此类名 -->
      <span class="iconfont" :class="item.iconText"></span>
      <!-- 文字 -->
      <span>{{ item.text }}</span>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      activeIndex: 0, //高亮元素下标
    }
  },
  methods: {
    clickFn(index,componentName) {
      this.activeIndex = index
      this.$emit('changeCom', componentName)//调用父级里的函数，传参为后面的值
    },
  },
  props: {
    list: {
      type: Array,
      required: true,
      Validator(val) {
        // val 就是我们传过来的数据，此函数中我们可以返回true，false
        // 如果返回true说明通过验证，返回false代表未通过验证
        if (val.length < 2 || val.length > 5) {
          console.error('props list must between 2 and 5') //未通过时提示报错
          return false
        }
        return true
      },
    },
  },
}
</script>

<style lang="less" scoped>
.my-tab-bar {
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 50px;
  border-top: 1px solid #ccc;
  display: flex;
  justify-content: space-around;
  align-items: center;
  background-color: white;
  .tab-item {
    display: flex;
    flex-direction: column;
    align-items: center;
  }
}

.current {
  color: #1d7bff;
}
</style>
